Turmeric is a rhizomatous herbaceous perennial plant (Curcuma longa) of the ginger family, Zingiberaceae. It is native to southern Asia, requiring temperatures between 20 and 30 °C (68 and 86 °F) and a considerable amount of annual rainfall to thrive. Plants are gathered annually for their rhizomes and propagated from some of those rhizomes in the following season.Wikipedia
The yellow spice found in many curries, contains curcumin, which also has powerful anti-inflammatory and antioxidant properties. It may even prove useful in treating Alzheimer's.